Ethanol (E10) is a strong water absorber that attracts water into gas.
Follow simple precautions to decrease risk and help safely manage E10 fuel blends.
E10 gas has a maximum shelf life of only 3 months under ideal environmental conditions, and can absorb excess water into gas in only a few weeks or less. Only 2-3 teaspoons water/gallon will phase separate E10 gas. Ethanol blends absorb 40-50 times more water, compared to 100% (non-alcohol) gasoline.
Marine engines and engines that have a vented fuel system (E.G. motorcycles, lawn equipment) and those that reside in humid environments have the greatest risk for E10 water contamination.
1. Removing and discarding fuel is the best method to treat E10 gas that is grossly contaminated with excess water.
Replace with new, fresh high quality gasoline, preferably non-ethanol blend. (Check at pump).
2. Risky, but worth mentioning...
If you have less than 1/2 tank gas remaining, we suggest you fill the tank up with very high octane gas (91-93 or better) and quickly run gas through tank.
When empty, make sure tank walls are clean and dry and fill-up with non-ethanol gas or lowest ethanol percent gas available.
(Check % gas at pump to find lower blend or non-ethanol 100% gasoline.). Quik-Check indicator solution can be used to confirm gasoline and gas tank is water-free and ethanol-free.
We recommend adding an octane enhancer, such as Octane Boost 104 after removing water from E10 gas, "because octane-enhancing ethanol" chemically joins with water and will be removed with water. Removing ethanol + water lower layer from gas drops the octane about 2-3 points.
3.Hire a professional - Mobile on-site fuel tank cleaning service company. Often referred to as "fuel-polishing - filtering - gas purifying - tank cleaning". This is an effective solution - The only reason we placed it at #3 is because professional treatments are often too costly for a small engine/fuel tank.
4. Use gas additives with caution. Water can also be removed from phase-separated fuel by using some of the newer "water removal" additives in the market such as Hydroburn G®. "Water-removing" gas additives almost always contain very strong solvents and alcohol, so always consider other (safer) options before use. When used improperly, additives that contain strong solvents, emulsifiers and/or high alcohol can cause unnecessary damage to engine and parts.
Removing water from E10 gas, always requires correcting octane rating. Pure ethanol has an octane of about 115. When manually removing water, octane enhancing ethanol is also removed - We recommend you check octane reading and add an octane enhancing additive, if necessary. Running an engine on below recommended octane gas can cause major and costly damage.
Caution: Always check that additve product is recommended by your engine manufacturer before use.
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One drop of concentrated Quik Check instantly checks gasoline for water contamination.
NON-additive precautions are always your best method to avoid water contamination of E10 gasoline.
For engines at very high risk for water contamination,
(E.G. prolonged storage and marine engines),
preventive use of a petroleum-based fuel stabilizer may be necessary with E10 gas.
We recommend Gas Shok which is the most effective product we have tested; There are many other petroleum-based gasoline stabilizers in the market such as Stabil and Startron.
1. Avoid using unnecessary fuel additive products that contain alcohol and/or water absorbing chemicals for "prevention".
2. Install a water separator filter or equipment in your engine - Check and replace filters often since they will clog quickly with E10 gasoline. We recommend Racor filters of at least 10-12 micron filtering capability.
3. Check fuel lines, caps, seals are intact and sealed to avoid unnecessary water entry in fuel system.
4. Replace gas often - every 1-2 weeks in high risk conditions.
Common symptoms of excess water in gas:
Stalling, hesitation, inability to start engine. Phase separation. Vapor lock or fuel starvation.
Corrosion and rusting of engine parts. Clogging of water separator filters.
Piston/bore failure through knock/pre-ignition - Corrosion of spark plugs. More.
IMAGE: Quik-Check Test Results - Gas with and without ethanol/water.
Right: Non-ethanol gas (no alcohol or water) 100% gasoline.